Hospitals & Services
Myocardial agents such as Sestamibi and Tetrafosmin are markers for viable, perfused myocardium. A perfusion abnormality on an exercise scan that returns to normal on a repeat rest study indicates reversible myocardial ischaemia.
Myocardial Perfusion Scans (MPS) are useful in assessing the extent and severity of myocardial ischaemia. It is critical to correlate the results of ECG testing and clinical data with scan results. MPS aid in pre-operative evaluation by helping to determine the amount of scar versus ischaemia present. The scan is often used to assess the significance of an equivocal stenosis seen on angiogram and to triage patients into medical or surgical management programs. The MPS also provide valuable data on LV size, volume and LVEF.
The greatest strength of MPS are their prognostic value. A negative MPS predicts a low risk and low annualised cardiac event rate of 0.6% per year for 3 years.
Detection and evaluation of known or suspected coronary artery disease.
Follow up of medical or surgical therapy of coronary artery disease.
The patient should fast at least 3 hours prior to the Rest study and have only a light lunch before the Stress study.
The patient should not have any food or drinks containing caffeine (tea, coffee, coke, chocolate) for 24 hours before the first study and until both studies are complete.
The patient should withdraw from beta-blockers for 48 hours (from the day before the stress study, continuing until the end of the study).
Nitrates and calcium channel blockers must be stopped for 24 hours before the study.
Myocardial Rest and Stress studies take approx. 2 hours each. They are usually performed on the same day (Rest Study in the morning and Stress Study in the afternoon) but they can be on separate days if required.
On arrival, an IV luer is inserted and ECG leads are attached. All metal items (including bra) must be removed from the chest area.
There is a waiting time of approx. 30min between IV injection and scanning. Each scan takes about 20 minutes.
The Stress study can be achieved by exercise bike, Persantin, Dobutamine, Adenosine or a combination of exercise and pharmacological stress. ECG recordings are made throughout the study and the injection is given after reaching peak heart rate.